Abstract

The response of eleven Indian cultivars of pigeon pea for in vitro multiple shoot bud induction and regeneration from plumule junction explants under variable concentration of 6-benzyl amino purine (BAP), kinetin and thiadiazuron (TDZ) was assessed in the present study. The cultivar IPA-3088 showed best response with a maximum of 20 buds per explants in Murashige and Skoog (MS) media supplemented with 0.05 mgL^-1 TDZ. Among the hormones tested, lower concentration of TDZ gave the best response for these cultivars though higher concentration of BAP was also effective in multiple shoot bud induction and regeneration from plumule junction explants. The elongation of multiple shoot buds was achieved in the same medium and the nature of the regenerants in most of the cases was shoots, though in few cases shoot buds and shoot primoridia were also observed. Rooting of plumule junction derived shootlets was found to be better in the presence of NAA as compared to IAA and IBA for most of the cultivars producing maximum number of primary roots. The best responding cultivar IPA 3088 showed efficient rooting in the presence of 0.2 mgL^-1 of NAA. The regenerated plantlets were acclimatized in soil with percentage of acclimatization varying from 40-80% for different cultivars.

Key words: Pigeon pea, cultivars, multiple shoot bud induction, organogenesis, acclimatization, elongation, Cajanus cajan (L) Mill sp.